sound/core/compress_offload.c

   1 /*
   2  *  compress_core.c - compress offload core
   3  *
   4  *  Copyright (C) 2011 Intel Corporation
   5  *  Authors:    Vinod Koul <vinod.koul@linux.intel.com>
   6  *              Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
   7  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; version 2 of the License.
  12  *
  13  *  This program is distributed in the hope that it will be useful, but
  14  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License along
  19  *  with this program; if not, write to the Free Software Foundation, Inc.,
  20  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  21  *
  22  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  23  *
  24  */
  25 #define FORMAT(fmt) "%s: %d: " fmt, __func__, __LINE__
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " FORMAT(fmt)
  27
  28 #include <linux/file.h>
  29 #include <linux/fs.h>
  30 #include <linux/list.h>
  31 #include <linux/math64.h>
  32 #include <linux/mm.h>
  33 #include <linux/mutex.h>
  34 #include <linux/poll.h>
  35 #include <linux/slab.h>
  36 #include <linux/sched.h>
  37 #include <linux/types.h>
  38 #include <linux/uio.h>
  39 #include <linux/uaccess.h>
  40 #include <linux/module.h>
  41 #include <sound/core.h>
  42 #include <sound/initval.h>
  43 #include <sound/compress_params.h>
  44 #include <sound/compress_offload.h>
  45 #include <sound/compress_driver.h>
  46
  47 /* TODO:
  48  * - add substream support for multiple devices in case of
  49  *      SND_DYNAMIC_MINORS is not used
  50  * - Multiple node representation
  51  *      driver should be able to register multiple nodes
  52  */
  53
  54 static DEFINE_MUTEX(device_mutex);
  55
  56 struct snd_compr_file {
  57         unsigned long caps;
  58         struct snd_compr_stream stream;
  59 };
  60
  61 /*
  62  * a note on stream states used:
  63  * we use follwing states in the compressed core
  64  * SNDRV_PCM_STATE_OPEN: When stream has been opened.
  65  * SNDRV_PCM_STATE_SETUP: When stream has been initialized. This is done by
  66  *      calling SNDRV_COMPRESS_SET_PARAMS. running streams will come to this
  67  *      state at stop by calling SNDRV_COMPRESS_STOP, or at end of drain.
  68  * SNDRV_PCM_STATE_RUNNING: When stream has been started and is
  69  *      decoding/encoding and rendering/capturing data.
  70  * SNDRV_PCM_STATE_DRAINING: When stream is draining current data. This is done
  71  *      by calling SNDRV_COMPRESS_DRAIN.
  72  * SNDRV_PCM_STATE_PAUSED: When stream is paused. This is done by calling
  73  *      SNDRV_COMPRESS_PAUSE. It can be stopped or resumed by calling
  74  *      SNDRV_COMPRESS_STOP or SNDRV_COMPRESS_RESUME respectively.
  75  */
  76 static int snd_compr_open(struct inode *inode, struct file *f)
  77 {
  78         struct snd_compr *compr;
  79         struct snd_compr_file *data;
  80         struct snd_compr_runtime *runtime;
  81         enum snd_compr_direction dirn;
  82         int maj = imajor(inode);
  83         int ret;
  84
  85         if ((f->f_flags & O_ACCMODE) == O_WRONLY)
  86                 dirn = SND_COMPRESS_PLAYBACK;
  87         else if ((f->f_flags & O_ACCMODE) == O_RDONLY)
  88                 dirn = SND_COMPRESS_CAPTURE;
  89         else
  90                 return -EINVAL;
  91
  92         if (maj == snd_major)
  93                 compr = snd_lookup_minor_data(iminor(inode),
  94                                         SNDRV_DEVICE_TYPE_COMPRESS);
  95         else
  96                 return -EBADFD;
  97
  98         if (compr == NULL) {
  99                 pr_err("no device data!!!\n");
 100                 return -ENODEV;
 101         }
 102
 103         if (dirn != compr->direction) {
 104                 pr_err("this device doesn't support this direction\n");
 105                 snd_card_unref(compr->card);
 106                 return -EINVAL;
 107         }
 108
 109         data = kzalloc(sizeof(*data), GFP_KERNEL);
 110         if (!data) {
 111                 snd_card_unref(compr->card);
 112                 return -ENOMEM;
 113         }
 114         data->stream.ops = compr->ops;
 115         data->stream.direction = dirn;
 116         data->stream.private_data = compr->private_data;
 117         data->stream.device = compr;
 118         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 119         if (!runtime) {
 120                 kfree(data);
 121                 snd_card_unref(compr->card);
 122                 return -ENOMEM;
 123         }
 124         runtime->state = SNDRV_PCM_STATE_OPEN;
 125         init_waitqueue_head(&runtime->sleep);
 126         data->stream.runtime = runtime;
 127         f->private_data = (void *)data;
 128         mutex_lock(&compr->lock);
 129         ret = compr->ops->open(&data->stream);
 130         mutex_unlock(&compr->lock);
 131         if (ret) {
 132                 kfree(runtime);
 133                 kfree(data);
 134         }
 135         snd_card_unref(compr->card);
 136         return 0;
 137 }
 138
 139 static int snd_compr_free(struct inode *inode, struct file *f)
 140 {
 141         struct snd_compr_file *data = f->private_data;
 142         data->stream.ops->free(&data->stream);
 143         kfree(data->stream.runtime->buffer);
 144         kfree(data->stream.runtime);
 145         kfree(data);
 146         return 0;
 147 }
 148
 149 static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
 150                 struct snd_compr_tstamp *tstamp)
 151 {
 152         if (!stream->ops->pointer)
 153                 return -ENOTSUPP;
 154         stream->ops->pointer(stream, tstamp);
 155         pr_debug("dsp consumed till %d total %d bytes\n",
 156                 tstamp->byte_offset, tstamp->copied_total);
 157         if (stream->direction == SND_COMPRESS_PLAYBACK)
 158                 stream->runtime->total_bytes_transferred = tstamp->copied_total;
 159         else
 160                 stream->runtime->total_bytes_available = tstamp->copied_total;
 161         return 0;
 162 }
 163
 164 static size_t snd_compr_calc_avail(struct snd_compr_stream *stream,
 165                 struct snd_compr_avail *avail)
 166 {
 167         memset(avail, 0, sizeof(*avail));
 168         snd_compr_update_tstamp(stream, &avail->tstamp);
 169         /* Still need to return avail even if tstamp can't be filled in */
 170
 171         if (stream->runtime->total_bytes_available == 0 &&
 172                         stream->runtime->state == SNDRV_PCM_STATE_SETUP &&
 173                         stream->direction == SND_COMPRESS_PLAYBACK) {
 174                 pr_debug("detected init and someone forgot to do a write\n");
 175                 return stream->runtime->buffer_size;
 176         }
 177         pr_debug("app wrote %lld, DSP consumed %lld\n",
 178                         stream->runtime->total_bytes_available,
 179                         stream->runtime->total_bytes_transferred);
 180         if (stream->runtime->total_bytes_available ==
 181                                 stream->runtime->total_bytes_transferred) {
 182                 if (stream->direction == SND_COMPRESS_PLAYBACK) {
 183                         pr_debug("both pointers are same, returning full avail\n");
 184                         return stream->runtime->buffer_size;
 185                 } else {
 186                         pr_debug("both pointers are same, returning no avail\n");
 187                         return 0;
 188                 }
 189         }
 190
 191         avail->avail = stream->runtime->total_bytes_available -
 192                         stream->runtime->total_bytes_transferred;
 193         if (stream->direction == SND_COMPRESS_PLAYBACK)
 194                 avail->avail = stream->runtime->buffer_size - avail->avail;
 195
 196         pr_debug("ret avail as %lld\n", avail->avail);
 197         return avail->avail;
 198 }
 199
 200 static inline size_t snd_compr_get_avail(struct snd_compr_stream *stream)
 201 {
 202         struct snd_compr_avail avail;
 203
 204         return snd_compr_calc_avail(stream, &avail);
 205 }
 206
 207 static int
 208 snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg)
 209 {
 210         struct snd_compr_avail ioctl_avail;
 211         size_t avail;
 212
 213         avail = snd_compr_calc_avail(stream, &ioctl_avail);
 214         ioctl_avail.avail = avail;
 215
 216         if (copy_to_user((__u64 __user *)arg,
 217                                 &ioctl_avail, sizeof(ioctl_avail)))
 218                 return -EFAULT;
 219         return 0;
 220 }
 221
 222 static int snd_compr_write_data(struct snd_compr_stream *stream,
 223                const char __user *buf, size_t count)
 224 {
 225         void *dstn;
 226         size_t copy;
 227         struct snd_compr_runtime *runtime = stream->runtime;
 228         /* 64-bit Modulus */
 229         u64 app_pointer = div64_u64(runtime->total_bytes_available,
 230                                     runtime->buffer_size);
 231         app_pointer = runtime->total_bytes_available -
 232                       (app_pointer * runtime->buffer_size);
 233
 234         dstn = runtime->buffer + app_pointer;
 235         pr_debug("copying %ld at %lld\n",
 236                         (unsigned long)count, app_pointer);
 237         if (count < runtime->buffer_size - app_pointer) {
 238                 if (copy_from_user(dstn, buf, count))
 239                         return -EFAULT;
 240         } else {
 241                 copy = runtime->buffer_size - app_pointer;
 242                 if (copy_from_user(dstn, buf, copy))
 243                         return -EFAULT;
 244                 if (copy_from_user(runtime->buffer, buf + copy, count - copy))
 245                         return -EFAULT;
 246         }
 247         /* if DSP cares, let it know data has been written */
 248         if (stream->ops->ack)
 249                 stream->ops->ack(stream, count);
 250         return count;
 251 }
 252
 253 static ssize_t snd_compr_write(struct file *f, const char __user *buf,
 254                 size_t count, loff_t *offset)
 255 {
 256         struct snd_compr_file *data = f->private_data;
 257         struct snd_compr_stream *stream;
 258         size_t avail;
 259         int retval;
 260
 261         if (snd_BUG_ON(!data))
 262                 return -EFAULT;
 263
 264         stream = &data->stream;
 265         mutex_lock(&stream->device->lock);
 266         /* write is allowed when stream is running or has been steup */
 267         if (stream->runtime->state != SNDRV_PCM_STATE_SETUP &&
 268                         stream->runtime->state != SNDRV_PCM_STATE_RUNNING) {
 269                 mutex_unlock(&stream->device->lock);
 270                 return -EBADFD;
 271         }
 272
 273         avail = snd_compr_get_avail(stream);
 274         pr_debug("avail returned %ld\n", (unsigned long)avail);
 275         /* calculate how much we can write to buffer */
 276         if (avail > count)
 277                 avail = count;
 278
 279         if (stream->ops->copy) {
 280                 char __user* cbuf = (char __user*)buf;
 281                 retval = stream->ops->copy(stream, cbuf, avail);
 282         } else {
 283                 retval = snd_compr_write_data(stream, buf, avail);
 284         }
 285         if (retval > 0)
 286                 stream->runtime->total_bytes_available += retval;
 287
 288         /* while initiating the stream, write should be called before START
 289          * call, so in setup move state */
 290         if (stream->runtime->state == SNDRV_PCM_STATE_SETUP) {
 291                 stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
 292                 pr_debug("stream prepared, Houston we are good to go\n");
 293         }
 294
 295         mutex_unlock(&stream->device->lock);
 296         return retval;
 297 }
 298
 299
 300 static ssize_t snd_compr_read(struct file *f, char __user *buf,
 301                 size_t count, loff_t *offset)
 302 {
 303         struct snd_compr_file *data = f->private_data;
 304         struct snd_compr_stream *stream;
 305         size_t avail;
 306         int retval;
 307
 308         if (snd_BUG_ON(!data))
 309                 return -EFAULT;
 310
 311         stream = &data->stream;
 312         mutex_lock(&stream->device->lock);
 313
 314         /* read is allowed when stream is running, paused, draining and setup
 315          * (yes setup is state which we transition to after stop, so if user
 316          * wants to read data after stop we allow that)
 317          */
 318         switch (stream->runtime->state) {
 319         case SNDRV_PCM_STATE_OPEN:
 320         case SNDRV_PCM_STATE_PREPARED:
 321         case SNDRV_PCM_STATE_XRUN:
 322         case SNDRV_PCM_STATE_SUSPENDED:
 323         case SNDRV_PCM_STATE_DISCONNECTED:
 324                 retval = -EBADFD;
 325                 goto out;
 326         }
 327
 328         avail = snd_compr_get_avail(stream);
 329         pr_debug("avail returned %ld\n", (unsigned long)avail);
 330         /* calculate how much we can read from buffer */
 331         if (avail > count)
 332                 avail = count;
 333
 334         if (stream->ops->copy) {
 335                 retval = stream->ops->copy(stream, buf, avail);
 336         } else {
 337                 retval = -ENXIO;
 338                 goto out;
 339         }
 340         if (retval > 0)
 341                 stream->runtime->total_bytes_transferred += retval;
 342
 343 out:
 344         mutex_unlock(&stream->device->lock);
 345         return retval;
 346 }
 347
 348 static int snd_compr_mmap(struct file *f, struct vm_area_struct *vma)
 349 {
 350         return -ENXIO;
 351 }
 352
 353 static inline int snd_compr_get_poll(struct snd_compr_stream *stream)
 354 {
 355         if (stream->direction == SND_COMPRESS_PLAYBACK)
 356                 return POLLOUT | POLLWRNORM;
 357         else
 358                 return POLLIN | POLLRDNORM;
 359 }
 360
 361 static unsigned int snd_compr_poll(struct file *f, poll_table *wait)
 362 {
 363         struct snd_compr_file *data = f->private_data;
 364         struct snd_compr_stream *stream;
 365         size_t avail;
 366         int retval = 0;
 367
 368         if (snd_BUG_ON(!data))
 369                 return -EFAULT;
 370         stream = &data->stream;
 371         if (snd_BUG_ON(!stream))
 372                 return -EFAULT;
 373
 374         mutex_lock(&stream->device->lock);
 375         if (stream->runtime->state == SNDRV_PCM_STATE_PAUSED ||
 376                         stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
 377                 retval = -EBADFD;
 378                 goto out;
 379         }
 380         poll_wait(f, &stream->runtime->sleep, wait);
 381
 382         avail = snd_compr_get_avail(stream);
 383         pr_debug("avail is %ld\n", (unsigned long)avail);
 384         /* check if we have at least one fragment to fill */
 385         switch (stream->runtime->state) {
 386         case SNDRV_PCM_STATE_DRAINING:
 387                 /* stream has been woken up after drain is complete
 388                  * draining done so set stream state to stopped
 389                  */
 390                 retval = snd_compr_get_poll(stream);
 391                 stream->runtime->state = SNDRV_PCM_STATE_SETUP;
 392                 break;
 393         case SNDRV_PCM_STATE_RUNNING:
 394         case SNDRV_PCM_STATE_PREPARED:
 395         case SNDRV_PCM_STATE_PAUSED:
 396                 if (avail >= stream->runtime->fragment_size)
 397                         retval = snd_compr_get_poll(stream);
 398                 break;
 399         default:
 400                 if (stream->direction == SND_COMPRESS_PLAYBACK)
 401                         retval = POLLOUT | POLLWRNORM | POLLERR;
 402                 else
 403                         retval = POLLIN | POLLRDNORM | POLLERR;
 404                 break;
 405         }
 406 out:
 407         mutex_unlock(&stream->device->lock);
 408         return retval;
 409 }
 410
 411 static int
 412 snd_compr_get_caps(struct snd_compr_stream *stream, unsigned long arg)
 413 {
 414         int retval;
 415         struct snd_compr_caps caps;
 416
 417         if (!stream->ops->get_caps)
 418                 return -ENXIO;
 419
 420         memset(&caps, 0, sizeof(caps));
 421         retval = stream->ops->get_caps(stream, &caps);
 422         if (retval)
 423                 goto out;
 424         if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 425                 retval = -EFAULT;
 426 out:
 427         return retval;
 428 }
 429
 430 static int
 431 snd_compr_get_codec_caps(struct snd_compr_stream *stream, unsigned long arg)
 432 {
 433         int retval;
 434         struct snd_compr_codec_caps *caps;
 435
 436         if (!stream->ops->get_codec_caps)
 437                 return -ENXIO;
 438
 439         caps = kzalloc(sizeof(*caps), GFP_KERNEL);
 440         if (!caps)
 441                 return -ENOMEM;
 442
 443         retval = stream->ops->get_codec_caps(stream, caps);
 444         if (retval)
 445                 goto out;
 446         if (copy_to_user((void __user *)arg, caps, sizeof(*caps)))
 447                 retval = -EFAULT;
 448
 449 out:
 450         kfree(caps);
 451         return retval;
 452 }
 453
 454 /* revisit this with snd_pcm_preallocate_xxx */
 455 static int snd_compr_allocate_buffer(struct snd_compr_stream *stream,
 456                 struct snd_compr_params *params)
 457 {
 458         unsigned int buffer_size;
 459         void *buffer;
 460
 461         buffer_size = params->buffer.fragment_size * params->buffer.fragments;
 462         if (stream->ops->copy) {
 463                 buffer = NULL;
 464                 /* if copy is defined the driver will be required to copy
 465                  * the data from core
 466                  */
 467         } else {
 468                 buffer = kmalloc(buffer_size, GFP_KERNEL);
 469                 if (!buffer)
 470                         return -ENOMEM;
 471         }
 472         stream->runtime->fragment_size = params->buffer.fragment_size;
 473         stream->runtime->fragments = params->buffer.fragments;
 474         stream->runtime->buffer = buffer;
 475         stream->runtime->buffer_size = buffer_size;
 476         return 0;
 477 }
 478
 479 static int snd_compress_check_input(struct snd_compr_params *params)
 480 {
 481         /* first let's check the buffer parameter's */
 482         if (params->buffer.fragment_size == 0 ||
 483                         params->buffer.fragments > SIZE_MAX / params->buffer.fragment_size)
 484                 return -EINVAL;
 485
 486         /* now codec parameters */
 487         if (params->codec.id == 0 || params->codec.id > SND_AUDIOCODEC_MAX)
 488                 return -EINVAL;
 489
 490         if (params->codec.ch_in == 0 || params->codec.ch_out == 0)
 491                 return -EINVAL;
 492
 493         if (!(params->codec.sample_rate & SNDRV_PCM_RATE_8000_192000))
 494                 return -EINVAL;
 495
 496         return 0;
 497 }
 498
 499 static int
 500 snd_compr_set_params(struct snd_compr_stream *stream, unsigned long arg)
 501 {
 502         struct snd_compr_params *params;
 503         int retval;
 504
 505         if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) {
 506                 /*
 507                  * we should allow parameter change only when stream has been
 508                  * opened not in other cases
 509                  */
 510                 params = kmalloc(sizeof(*params), GFP_KERNEL);
 511                 if (!params)
 512                         return -ENOMEM;
 513                 if (copy_from_user(params, (void __user *)arg, sizeof(*params))) {
 514                         retval = -EFAULT;
 515                         goto out;
 516                 }
 517
 518                 retval = snd_compress_check_input(params);
 519                 if (retval)
 520                         goto out;
 521
 522                 retval = snd_compr_allocate_buffer(stream, params);
 523                 if (retval) {
 524                         retval = -ENOMEM;
 525                         goto out;
 526                 }
 527
 528                 retval = stream->ops->set_params(stream, params);
 529                 if (retval)
 530                         goto out;
 531
 532                 stream->metadata_set = false;
 533                 stream->next_track = false;
 534
 535                 if (stream->direction == SND_COMPRESS_PLAYBACK)
 536                         stream->runtime->state = SNDRV_PCM_STATE_SETUP;
 537                 else
 538                         stream->runtime->state = SNDRV_PCM_STATE_PREPARED;
 539         } else {
 540                 return -EPERM;
 541         }
 542 out:
 543         kfree(params);
 544         return retval;
 545 }
 546
 547 static int
 548 snd_compr_get_params(struct snd_compr_stream *stream, unsigned long arg)
 549 {
 550         struct snd_codec *params;
 551         int retval;
 552
 553         if (!stream->ops->get_params)
 554                 return -EBADFD;
 555
 556         params = kzalloc(sizeof(*params), GFP_KERNEL);
 557         if (!params)
 558                 return -ENOMEM;
 559         retval = stream->ops->get_params(stream, params);
 560         if (retval)
 561                 goto out;
 562         if (copy_to_user((char __user *)arg, params, sizeof(*params)))
 563                 retval = -EFAULT;
 564
 565 out:
 566         kfree(params);
 567         return retval;
 568 }
 569
 570 static int
 571 snd_compr_get_metadata(struct snd_compr_stream *stream, unsigned long arg)
 572 {
 573         struct snd_compr_metadata metadata;
 574         int retval;
 575
 576         if (!stream->ops->get_metadata)
 577                 return -ENXIO;
 578
 579         if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
 580                 return -EFAULT;
 581
 582         retval = stream->ops->get_metadata(stream, &metadata);
 583         if (retval != 0)
 584                 return retval;
 585
 586         if (copy_to_user((void __user *)arg, &metadata, sizeof(metadata)))
 587                 return -EFAULT;
 588
 589         return 0;
 590 }
 591
 592 static int
 593 snd_compr_set_metadata(struct snd_compr_stream *stream, unsigned long arg)
 594 {
 595         struct snd_compr_metadata metadata;
 596         int retval;
 597
 598         if (!stream->ops->set_metadata)
 599                 return -ENXIO;
 600         /*
 601         * we should allow parameter change only when stream has been
 602         * opened not in other cases
 603         */
 604         if (copy_from_user(&metadata, (void __user *)arg, sizeof(metadata)))
 605                 return -EFAULT;
 606
 607         retval = stream->ops->set_metadata(stream, &metadata);
 608         stream->metadata_set = true;
 609
 610         return retval;
 611 }
 612
 613 static inline int
 614 snd_compr_tstamp(struct snd_compr_stream *stream, unsigned long arg)
 615 {
 616         struct snd_compr_tstamp tstamp = {0};
 617         int ret;
 618
 619         ret = snd_compr_update_tstamp(stream, &tstamp);
 620         if (ret == 0)
 621                 ret = copy_to_user((struct snd_compr_tstamp __user *)arg,
 622                         &tstamp, sizeof(tstamp)) ? -EFAULT : 0;
 623         return ret;
 624 }
 625
 626 static int snd_compr_pause(struct snd_compr_stream *stream)
 627 {
 628         int retval;
 629
 630         if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
 631                 return -EPERM;
 632         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_PUSH);
 633         if (!retval)
 634                 stream->runtime->state = SNDRV_PCM_STATE_PAUSED;
 635         return retval;
 636 }
 637
 638 static int snd_compr_resume(struct snd_compr_stream *stream)
 639 {
 640         int retval;
 641
 642         if (stream->runtime->state != SNDRV_PCM_STATE_PAUSED)
 643                 return -EPERM;
 644         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
 645         if (!retval)
 646                 stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
 647         return retval;
 648 }
 649
 650 static int snd_compr_start(struct snd_compr_stream *stream)
 651 {
 652         int retval;
 653
 654         if (stream->runtime->state != SNDRV_PCM_STATE_PREPARED)
 655                 return -EPERM;
 656         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_START);
 657         if (!retval)
 658                 stream->runtime->state = SNDRV_PCM_STATE_RUNNING;
 659         return retval;
 660 }
 661
 662 static int snd_compr_stop(struct snd_compr_stream *stream)
 663 {
 664         int retval;
 665
 666         if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
 667                         stream->runtime->state == SNDRV_PCM_STATE_SETUP)
 668                 return -EPERM;
 669         retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
 670         if (!retval) {
 671                 stream->runtime->state = SNDRV_PCM_STATE_SETUP;
 672                 wake_up(&stream->runtime->sleep);
 673                 stream->runtime->total_bytes_available = 0;
 674                 stream->runtime->total_bytes_transferred = 0;
 675         }
 676         return retval;
 677 }
 678
 679 static int snd_compr_drain(struct snd_compr_stream *stream)
 680 {
 681         int retval;
 682
 683         if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
 684                         stream->runtime->state == SNDRV_PCM_STATE_SETUP)
 685                 return -EPERM;
 686         retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
 687         if (!retval) {
 688                 stream->runtime->state = SNDRV_PCM_STATE_DRAINING;
 689                 wake_up(&stream->runtime->sleep);
 690         }
 691         return retval;
 692 }
 693
 694 static int snd_compr_next_track(struct snd_compr_stream *stream)
 695 {
 696         int retval;
 697
 698         /* only a running stream can transition to next track */
 699         if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
 700                 return -EPERM;
 701
 702         /* you can signal next track isf this is intended to be a gapless stream
 703          * and current track metadata is set
 704          */
 705         if (stream->metadata_set == false)
 706                 return -EPERM;
 707
 708         retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_NEXT_TRACK);
 709         if (retval != 0)
 710                 return retval;
 711         stream->metadata_set = false;
 712         stream->next_track = true;
 713         return 0;
 714 }
 715
 716 static int snd_compr_partial_drain(struct snd_compr_stream *stream)
 717 {
 718         int retval;
 719         if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
 720                         stream->runtime->state == SNDRV_PCM_STATE_SETUP)
 721                 return -EPERM;
 722         /* stream can be drained only when next track has been signalled */
 723         if (stream->next_track == false)
 724                 return -EPERM;
 725
 726         retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_PARTIAL_DRAIN);
 727
 728         stream->next_track = false;
 729         return retval;
 730 }
 731
 732 static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
 733 {
 734         struct snd_compr_file *data = f->private_data;
 735         struct snd_compr_stream *stream;
 736         int retval = -ENOTTY;
 737
 738         if (snd_BUG_ON(!data))
 739                 return -EFAULT;
 740         stream = &data->stream;
 741         if (snd_BUG_ON(!stream))
 742                 return -EFAULT;
 743         mutex_lock(&stream->device->lock);
 744         switch (_IOC_NR(cmd)) {
 745         case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
 746                 put_user(SNDRV_COMPRESS_VERSION,
 747                                 (int __user *)arg) ? -EFAULT : 0;
 748                 break;
 749         case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):
 750                 retval = snd_compr_get_caps(stream, arg);
 751                 break;
 752         case _IOC_NR(SNDRV_COMPRESS_GET_CODEC_CAPS):
 753                 retval = snd_compr_get_codec_caps(stream, arg);
 754                 break;
 755         case _IOC_NR(SNDRV_COMPRESS_SET_PARAMS):
 756                 retval = snd_compr_set_params(stream, arg);
 757                 break;
 758         case _IOC_NR(SNDRV_COMPRESS_GET_PARAMS):
 759                 retval = snd_compr_get_params(stream, arg);
 760                 break;
 761         case _IOC_NR(SNDRV_COMPRESS_SET_METADATA):
 762                 retval = snd_compr_set_metadata(stream, arg);
 763                 break;
 764         case _IOC_NR(SNDRV_COMPRESS_GET_METADATA):
 765                 retval = snd_compr_get_metadata(stream, arg);
 766                 break;
 767         case _IOC_NR(SNDRV_COMPRESS_TSTAMP):
 768                 retval = snd_compr_tstamp(stream, arg);
 769                 break;
 770         case _IOC_NR(SNDRV_COMPRESS_AVAIL):
 771                 retval = snd_compr_ioctl_avail(stream, arg);
 772                 break;
 773         case _IOC_NR(SNDRV_COMPRESS_PAUSE):
 774                 retval = snd_compr_pause(stream);
 775                 break;
 776         case _IOC_NR(SNDRV_COMPRESS_RESUME):
 777                 retval = snd_compr_resume(stream);
 778                 break;
 779         case _IOC_NR(SNDRV_COMPRESS_START):
 780                 retval = snd_compr_start(stream);
 781                 break;
 782         case _IOC_NR(SNDRV_COMPRESS_STOP):
 783                 retval = snd_compr_stop(stream);
 784                 break;
 785         case _IOC_NR(SNDRV_COMPRESS_DRAIN):
 786                 retval = snd_compr_drain(stream);
 787                 break;
 788         case _IOC_NR(SNDRV_COMPRESS_PARTIAL_DRAIN):
 789                 retval = snd_compr_partial_drain(stream);
 790                 break;
 791         case _IOC_NR(SNDRV_COMPRESS_NEXT_TRACK):
 792                 retval = snd_compr_next_track(stream);
 793                 break;
 794
 795         }
 796         mutex_unlock(&stream->device->lock);
 797         return retval;
 798 }
 799
 800 static const struct file_operations snd_compr_file_ops = {
 801                 .owner =        THIS_MODULE,
 802                 .open =         snd_compr_open,
 803                 .release =      snd_compr_free,
 804                 .write =        snd_compr_write,
 805                 .read =         snd_compr_read,
 806                 .unlocked_ioctl = snd_compr_ioctl,
 807                 .mmap =         snd_compr_mmap,
 808                 .poll =         snd_compr_poll,
 809 };
 810
 811 static int snd_compress_dev_register(struct snd_device *device)
 812 {
 813         int ret = -EINVAL;
 814         char str[16];
 815         struct snd_compr *compr;
 816
 817         if (snd_BUG_ON(!device || !device->device_data))
 818                 return -EBADFD;
 819         compr = device->device_data;
 820
 821         sprintf(str, "comprC%iD%i", compr->card->number, compr->device);
 822         pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
 823                         compr->direction);
 824         /* register compressed device */
 825         ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS, compr->card,
 826                         compr->device, &snd_compr_file_ops, compr, str);
 827         if (ret < 0) {
 828                 pr_err("snd_register_device failed\n %d", ret);
 829                 return ret;
 830         }
 831         return ret;
 832
 833 }
 834
 835 static int snd_compress_dev_disconnect(struct snd_device *device)
 836 {
 837         struct snd_compr *compr;
 838
 839         compr = device->device_data;
 840         snd_unregister_device(compr->direction, compr->card, compr->device);
 841         return 0;
 842 }
 843
 844 /*
 845  * snd_compress_new: create new compress device
 846  * @card: sound card pointer
 847  * @device: device number
 848  * @dirn: device direction, should be of type enum snd_compr_direction
 849  * @compr: compress device pointer
 850  */
 851 int snd_compress_new(struct snd_card *card, int device,
 852                         int dirn, struct snd_compr *compr)
 853 {
 854         static struct snd_device_ops ops = {
 855                 .dev_free = NULL,
 856                 .dev_register = snd_compress_dev_register,
 857                 .dev_disconnect = snd_compress_dev_disconnect,
 858         };
 859
 860         compr->card = card;
 861         compr->device = device;
 862         compr->direction = dirn;
 863         return snd_device_new(card, SNDRV_DEV_COMPRESS, compr, &ops);
 864 }
 865 EXPORT_SYMBOL_GPL(snd_compress_new);
 866
 867 static int snd_compress_add_device(struct snd_compr *device)
 868 {
 869         int ret;
 870
 871         if (!device->card)
 872                 return -EINVAL;
 873
 874         /* register the card */
 875         ret = snd_card_register(device->card);
 876         if (ret)
 877                 goto out;
 878         return 0;
 879
 880 out:
 881         pr_err("failed with %d\n", ret);
 882         return ret;
 883
 884 }
 885
 886 static int snd_compress_remove_device(struct snd_compr *device)
 887 {
 888         return snd_card_free(device->card);
 889 }
 890
 891 /**
 892  * snd_compress_register - register compressed device
 893  *
 894  * @device: compressed device to register
 895  */
 896 int snd_compress_register(struct snd_compr *device)
 897 {
 898         int retval;
 899
 900         if (device->name == NULL || device->dev == NULL || device->ops == NULL)
 901                 return -EINVAL;
 902
 903         pr_debug("Registering compressed device %s\n", device->name);
 904         if (snd_BUG_ON(!device->ops->open))
 905                 return -EINVAL;
 906         if (snd_BUG_ON(!device->ops->free))
 907                 return -EINVAL;
 908         if (snd_BUG_ON(!device->ops->set_params))
 909                 return -EINVAL;
 910         if (snd_BUG_ON(!device->ops->trigger))
 911                 return -EINVAL;
 912
 913         mutex_init(&device->lock);
 914
 915         /* register a compressed card */
 916         mutex_lock(&device_mutex);
 917         retval = snd_compress_add_device(device);
 918         mutex_unlock(&device_mutex);
 919         return retval;
 920 }
 921 EXPORT_SYMBOL_GPL(snd_compress_register);
 922
 923 int snd_compress_deregister(struct snd_compr *device)
 924 {
 925         pr_debug("Removing compressed device %s\n", device->name);
 926         mutex_lock(&device_mutex);
 927         snd_compress_remove_device(device);
 928         mutex_unlock(&device_mutex);
 929         return 0;
 930 }
 931 EXPORT_SYMBOL_GPL(snd_compress_deregister);
 932
 933 static int __init snd_compress_init(void)
 934 {
 935         return 0;
 936 }
 937
 938 static void __exit snd_compress_exit(void)
 939 {
 940 }
 941
 942 module_init(snd_compress_init);
 943 module_exit(snd_compress_exit);
 944
 945 MODULE_DESCRIPTION("ALSA Compressed offload framework");
 946 MODULE_AUTHOR("Vinod Koul <vinod.koul@linux.intel.com>");
 947 MODULE_LICENSE("GPL v2");